Based On The Embedded Linux Scheduling Research And Implementation Of Real-time

Into The post-PC era, mobile devices has become an important tool in people’s lives.In the field of mobile computing, embedded systems play an increasingly important role,and its advantage is that can be a better combination of microprocessor and itsproprietary software to achieve the maximum ratio of the cost of system operationefficiency. But with the development of microelectronic technology, a single chipintegrated number of transistors on the hundreds of millions of load on the system moreand more complex, resulting in real-time is becoming less and less, especially in somekey areas, such as automatic control, nuclear power plant, if you can not meet thereal-time requirements will result in irreparable consequences. Therefore, it is necessaryon the real-time embedded systems research.Real-time embedded systems, including the system response to external events,and the timeliness of task execution. Response to external events, called interrupts,including interrupt latency, interrupt, and interrupt handling phase. Processing ingeneral PC performance for scheduling tasks in a timely manner. Task schedulinginvolves scheduling algorithm, the scheduling policy. Today’s more mature schedulingalgorithms RM algorithm and EDF algorithms, and other scheduling algorithms arebased on it evolved. The RM algorithm is a static fixed-priority scheduling algorithm.Task priority and task cycle showed a monotonic function relationship. The EDFalgorithm is a dynamic scheduling, the scheduling algorithm has a higher CPUutilization.Through in-depth analysis of the Linux kernel scheduler framework, this Thesissummarized the thinking of the object-oriented design. Real-time Linux is not "realtime" by analysis the existing real-time scheduling policy, scheduling real-timeprotection mechanism for embedded Linux environment, in-depth analysis of the RM,EDF, and adaptive scheduling algorithm and the introduction of Linux kernel, thelast,The three scheduler based on the Apollo platform coding embedded Linux as aplatform through the experimental test data show that the three scheduler can guarantee real-time task execution, especially in applications with a feedback mechanism nextadaptive scheduling to ensure real-time nature of the task.